Abstract: Between 1949 and 1956, China built a social organization system that is neither the so-called "third sector" in Western countries nor a collection of civil associations. It is composed of three types of social organizations in broad sense:mass organizations led by the CCP, social organizations received re-accreditation, and non-registered resident mutual aid organizations. It is a specific type of adaptive political power construction that is driven by the joint-action of three forces:state-structured social organizations, social elite collaboration, and social members filling in the gap on marginal affairs. Among the three, the power and role of state-structured social organizations are the most evident and powerful, and they determine the space and strength of the latter two forces. Elite collaborative social organizations, except mass organizations, play a moderate role, while resident organizatoins handling periphery social issues are in the weakest position. In China, the social organization system created in this way is highly compatible with nation-building but weak in managing social affairs. In the following decades, the Chinese social organization system has witnessed noticeable changes. The three types of social organizations have all been expanded and the allocation of strength has also changed. However, there are always continuous or persistent characteristics that do not change, such as the CCP's leadership over the social organisation system, the rule of administrative regulations and the unity of all social elements for the nation-building. The above-discussed historical process shows that the future reform of China's social organization system will keep its focus on activating the social function of the three types of organisations while maintaining the tradition of a unified society under the state and regulation of social organizations.

Key words: social organization system, the state structuring, social cooperation, residents' mutual aid